Seeking sustainable pathway of crop production by optimizing planting structures and management practices from the perspective of water footprint

Water shortage threatens sustainable agriculture and food security globally. The Huanghuaihai Plain plays a critical role in ensuring China's food security, but at the expense of groundwater quantity and quality. Approaches that integrate crop production and environmental goals offer promise for achieving more sustainable water management in agriculture, yet little work has been done to link potential solutions with planting structure and resource management. The spatiotemporal variation of water footprint, water scarcity footprint, and green water occupancy rate for seven major crops, and the sustainability index and reduction potential of ten targeted reduction scenarios across 486 counties were quantitatively assessed in the Huanghuaihai Plain during 1985–2015. Total and gray water footprints dramatically increased by 59.5 % and 446.8 % from 1985 to 2015, respectively. The water scarcity footprint increased from 43.3 × 109 to 49.9 × 109 m3 and green water occupancy rate decreased from 37.8 % to 36.1 %. Among the single measures, reducing nitrogen input or its leaching would have the optimal reduction potential in WFtotal (reduced by 5.5–11.0 %), while adjusting planting structure would have the best sustainable performance. More importantly, the areas with the greatest reduction potential in blue water footprint by deficit irrigation and adjusting planting structure were located in the southeastern and middle parts of the plain, respectively, suggesting that differentiated strategies are required for regional water sustainability. The findings provide not only integrated approaches to inform targeted water management decision making in the Huanghuaihai Plain, but also best practices that may be applicable to other regions facing similar resource concerns.